Scrotal scintigraphy is a diagnostic nuclear medicine procedure that can be used, among other things, to evaluate acute scrotum (clinical picture associated with acute or episodic onset of pain in the scrotum and swelling of the scrotum; urologic emergency). Acute scrotum represents a sudden onset of pain in the testicle that can have a variety of causes. The most common reason for performing a testicular scintigraphy and for the occurrence of acute scrotum is testicular torsion (stalk rotation of the testis and epididymis), in which a sudden stalk rotation of the testis and epididymis results in a complete or incomplete interruption of the blood supply. As a result of this stalk rotation, hemorrhagic infarction (hemorrhage as tissue perishes) often occurs.
Indications (areas of application)
- Testicular torsion – in the context of testicular torsion, a sudden onset of severe pain in the affected testicle is typical. This usually radiates to the groin and kidney region. However, far more often than a sporting activity or an accident, a spontaneous torsion during sleep is named as the cause. If this pain occurs in the region, testicular scintigraphy is indicated as a procedure for detecting or differentiating differential diagnoses (diseases similar to the clinical picture – see below) in conjunction with other diagnostic procedures. Evident of testicular torsion, however, is only an invasive exposure of the testis.
- Torsion of the mesorchium (testicular mesentery (mesorchium), which serves to attach the testicle in the scrotum) – in this process, the testicle rotates against the epididymis, so that as a result there is painful inferior perfusion (inferior blood flow).
- Hydatid torsion (torsion of testicular or epididymal appendages) – this pathological (pathological) process represents a rotation of remaining tissue remnants of embryonic development, which leads to ischemia (lack of oxygen) of the hydatid. As a rule, children are affected. Due to the clinical similarity of hydatid torsion to testicular torsion, a precise diagnostic differentiation is necessary.
- Epididymitis (inflammation of the epididymis) – inflammation of the epididymis can also lead to the clinical picture of acute scrotum and must be diagnostically differentiated from testicular torsion. Since the disease is highly rare in childhood, the possibility that it could be testicular torsion must be considered even after the diagnosis has been made. Thus, if epididymitis is suspected, exposure of the testis must be performed in addition to scintigraphy.
- Ischemias (reduced blood flow) in systemic diseases – in the presence of a systemic disease such as sickle cell anemia (med. (med. : drepanocytosis; also sickle cell anemia) – genetic disease of erythrocytes (red blood cells); it belongs to the group of hemoglobinopathies (disorders of hemoglobin; formation of an irregular hemoglobin called sickle cell hemoglobin, HbS), ischemia (reduced blood flow) of the testis may occur. Thrombosis (venous occlusion) can also cause ischemia.
- Testicular infarction – a complete undersupply of the testis (after compression or due to thrombosis) is also detectable with testicular scintigraphy.
- Hemorrhage in testicular tumor
- Testicular trauma (in the newborn also birth trauma; injury).
Contraindications
There are no known contraindications.
Before the examination
- Clinical examination – testicular torsion may present with typical clinical signs such as Brunzel’s sign. Brunzel’s sign is a fixed, painful, and horizontal protrusion of the affected testis in the presence of testicular torsion. Severe pain is also typical in testicular torsion.
- Performance of other diagnostic procedures – before performing testicular scintigraphy, it is necessary to use non-radiation procedures such as sonography for diagnosis.
- Application of the radiopharmaceutical – To perform testicular scintigraphy, the radioactive 99mTechnetium-DTPA is used as a radiopharmaceutical. The radiopharmaceutical is applied intravenously. In adults, a radioactivity quantity of 400 MBq (millibecquerel) is used.During application, the patient should be in the supine position, with fixation of the penis.
The procedure
Testicular scintigraphy is a combination of static and dynamic scintigraphy. Thus, an assessment of the arterial perfusion of the testis and simultaneous imaging of the blood pool is possible. In contrast to other scintigraphic procedures, the assessment is exclusively visual. In the vast majority of studies, the procedure has been shown to be a valuable diagnostic tool, particularly in differentiating testicular torsion from an inflammatory process. However, because of the lack of radiation exposure, sonography is often primarily indicated.
After the examination
Following the course of the examination, plenty of fluids should be ingested to achieve adequate elimination of the radioactive pharmaceutical to minimize radiation exposure.
Potential complications
Intravenous administration of the radiopharmaceutical may result in local vascular and nerve lesions (injuries). Radiation exposure from the radionuclide used is considered to be rather low. Nevertheless, the theoretical risk of a radiation-induced late malignancy (leukemia or carcinoma) is increased, so that a risk-benefit assessment should be performed. Due to reduced bladder emptying, radiation exposure can be significantly higher than in normal cases. Because of this, abnormalities of bladder emptying should be addressed, particularly in the medical history.
